L:\usmle review 7 - Sinoe medical homepage.

accommodation but not in response to light. A VDRL test is positive. A CT scan of the spinal cord
would most likely demonstrate atrophy of which of the following structures
(A)
(B)
(C)
(D)
(E)
Dorsal column
Dorsal horn
Lateral column
Ventral column
Ventral horn
45. The correct answer is A. The patient has tabes dorsalis, which is a form of neurosyphilis
seen 10 to 25 years or longer after primary disease. The pupils described are Argyll Robertson
pupils and are considered diagnostic for neurosyphilis. Characteristically, the dorsal columns,
which contain the ascending tracts for sensory information, become atrophic, probably as a result
of damage to the dorsal root ganglion cells.
The dorsal gray horn (choice B) contains neurons that respond to sensory input.
The lateral column (choice C) contains both descending (e.g., lateral corticospinal, rubrospinal
tracts) and ascending (e.g., spinocerebellar tracts, spinothalamic tracts) tracts.
The ventral column (choice D) contains both descending (e.g., anterior corticospinal, tectospinal)
and ascending (e.g., spinothalamic) tracts.
The ventral horn (choice E) contains lower motor neurons.
46. An oncologist tells his patient that her laboratory results support a diagnosis of advanced
malignant melanoma with multiple metastases to the liver and brain. He also advises her that the
prognosis is poor. Which of the following is most likely to be the first statement that the patient will
make